AUTHOR=Xiang Yanhong , Jiang Youliang , Liu Saiqiu , Wu Jianhua , Liu Zhixiong , Zhu Ling , Xiong Lizhi , He Zeqiang , Wu Xianwen 

TITLE=Improved Electrochemical Performance of 0.5Li2MnO3·0.5LiNi0.5Mn0.5O2 Cathode Materials for Lithium Ion Batteries Synthesized by Ionic-Liquid-Assisted Hydrothermal Method

JOURNAL=Frontiers in Chemistry

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.00729

DOI=10.3389/fchem.2020.00729

ISSN=2296-2646

ABSTRACT=<p>Well-dispersed Li-rich Mn-based 0.5Li<sub>2</sub>MnO<sub>3</sub>·0.5LiNi0.5Mn<sub>0.5</sub>O<sub>2</sub> nanoparticles with diameter ranging from 50 to 100 nm are synthesized by a hydrothermal method in the presence of N-hexyl pyridinium tetrafluoroborate ionic liquid ([HPy][BF4]). The microstructures and electrochemical performance of the prepared cathode materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electrochemical measurements. The XRD results show that the sample prepared by ionic-liquid-assisted hydrothermal method exhibits a typical Li-rich Mn-based pure phase and lower cation mixing. SEM and TEM images indicate that the extent of particle agglomeration of the ionic-liquid-assisted sample is lower compared to the traditional hydrothermal sample. Electrochemical test results indicate that the materials synthesized by ionic-liquid-assisted hydrothermal method exhibit better rate capability and cyclability. Besides, electrochemical impedance spectroscopy (EIS) results suggest that the charge transfer resistance of 0.5Li<sub>2</sub>MnO<sub>3</sub>· 0.5LiNi0.5Mn<sub>0.5</sub>O<sub>2</sub> synthesized by ionic-liquid-assisted hydrothermal method is much lower, which enhances the reaction kinetics.</p>